WAEC SSCE - General Mathematics - 2019

Detalhes da Resposta

We can start by squaring each of the numbers in the expression: (27.63)\(^2\) = 762.9869 (12.37)\(^2\) = 153.4369 Now we can subtract the two squares: 762.9869 - 153.4369 = 609.55 Rounding the result to three significant figures, we get: 609.55 = 610 So (27.63)\(^2\) - (12.37)\(^2\) = 610.

Detalhes da Resposta

To express 0.003597 correct to three significant figures, we need to round off the number to the third digit after the decimal point. The third digit after the decimal point is 7. Since 7 is greater than or equal to 5, we need to round up the second digit after the decimal point. Therefore, the third digit becomes zero. Hence, the rounded value of 0.003597 correct to three significant figures is 0.00360. Therefore, the answer is: 0.00360.

Detalhes da Resposta

Detalhes da Resposta

In an arithmetic progression (AP), the terms are equally spaced. Let's call the common difference "d". If we have the first term "a" and the nth term "an", we can find the common difference using the formula: d = (an - a) / (n - 1) In this case, the fourth term is 37 and the first term is -20, so we can plug in the values into the formula: d = (37 - (-20)) / (4 - 1) = 57 / 3 = 19 So the common difference is 19.

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There are 5 + 6 + 7 = 18 pencils in the box. Since there are 6 green pencils, the probability of picking a green pencil at random is 6/18, which simplifies to 1/3. Therefore, the answer is \(\frac{1}{3}\).

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

If Bala sold an article for #6,900.00 and made a profit of 15%, this means that his cost price for the article was lower than the selling price by 15%. We can calculate his cost price as follows: Cost Price = Selling Price / (1 + Profit%) Cost Price = 6,900 / (1 + 0.15) Cost Price = 6,000 Therefore, Bala's cost price was #6,000.00, and he sold the article for #6,900.00, making a profit of #900.00. Now, we need to calculate the percentage profit he would have made if he sold the article for #6,600.00 instead of #6,900.00. To do this, we can use the following formula: Percentage Profit = (Profit / Cost Price) x 100% Percentage Profit = (6,600 - 6,000) / 6,000 x 100% Percentage Profit = 10% Therefore, if Bala had sold the article for #6,600.00 instead of #6,900.00, he would have made a profit of 10%. The correct option is 10%.

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We are given that \(\tan x = \frac{3}{4}\) and \(0 < x < 90^o\). Since \(\tan x = \frac{\sin x}{\cos x}\), we can rewrite the given equation as: \[\frac{\sin x}{\cos x} = \frac{3}{4}\] Multiplying both sides by \(\cos x\) gives us: \[\sin x = \frac{3}{4}\cos x\] Dividing both sides by \(2\sin x\) gives us: \[\frac{\cos x}{2\sin x} = \frac{\frac{4}{3}\sin x}{2\sin x} = \frac{4}{3} \cdot \frac{1}{2} = \frac{2}{3}\] Therefore, the value of \(\frac{\cos x}{2\sin x}\) is \(\frac{2}{3}\). Hence, the answer is: \(\frac{2}{3}\).

Detalhes da Resposta

Detalhes da Resposta

To evaluate the expression 2\(\sqrt{28} - 3\sqrt{50} + \sqrt{72}\), we need to simplify the square roots first. \(\sqrt{28} = 2\sqrt{7}\) \(\sqrt{50} = 5\sqrt{2}\) \(\sqrt{72} = 2\sqrt{18} = 2\sqrt{9}\sqrt{2} = 6\sqrt{2}\) Now that we have simplified the square roots, we can substitute the values back into the expression: 2\(\sqrt{28} - 3\sqrt{50} + \sqrt{72}\) = 2 * 2\(\sqrt{7}\) - 3 * 5\(\sqrt{2}\) + 6\(\sqrt{2}\) = 4\(\sqrt{7}\) - 3 * 5\(\sqrt{2}\) + 6\(\sqrt{2}\) = 4\(\sqrt{7}\) - 15\(\sqrt{2}\) + 6\(\sqrt{2}\) = 4\(\sqrt{7}\) - 9\(\sqrt{2}\) So the expression evaluates to 4\(\sqrt{7}\) - 9\(\sqrt{2}\).

Detalhes da Resposta

To find the length of the arc, we need to use the formula: Length of arc = \(\frac{\text{angle subtended by the arc}}{360^\circ} \times 2\pi r\) Here, the angle subtended by the arc is 72\(^o\) and the radius of the circle is 3.5 cm. We can substitute these values in the formula to get: Length of arc = \(\frac{72^\circ}{360^\circ} \times 2 \times \frac{22}{7} \times 3.5\) cm Simplifying this expression, we get: Length of arc = \(\frac{1}{5} \times \frac{44}{7} \times 3.5\) cm Length of arc = \(\frac{22}{5}\) cm Length of arc = 4.4 cm (approx.) Therefore, the length of the arc is 4.4 cm (option C).

Detalhes da Resposta

Detalhes da Resposta

The set T is the set of prime numbers less than or equal to 10, which are {2, 3, 5, 7}. The prime complement (T\(\prime\)) is the set of non-prime numbers less than or equal to 10, which are {1, 4, 6, 8, 10}. The set M is the set of odd numbers less than or equal to 10, which are {1, 3, 5, 7, 9}. The odd complement (M\(\prime\)) is the set of even numbers less than or equal to 10, which are {2, 4, 6, 8, 10}. Finally, the intersection of T\(\prime\) and M\(\prime\) is the set of numbers that are both non-prime and even, which is {4, 6, 8, 10}. So (T\(\prime\) n M\(\prime\)) = {4, 6, 8, 10}.

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

To factorize the given expression, we can use the distributive property of multiplication over addition. This means that we need to multiply each term in the first set of parentheses by each term in the second set of parentheses, and then simplify: (2x + 2y)(x - y) + (2x - 2y)(x + y) = 2x(x - y) + 2y(x - y) + 2x(x + y) - 2y(x + y) (using distributive property) = 2x^2 - 2xy + 2xy + 2y^2 + 2x^2 + 2xy - 2xy - 2y^2 (combining like terms) = 4x^2 - 4y^2 Therefore, the answer is 4(x - y)(x + y). Explanation: We can factorize the given expression by grouping the terms into two sets, each set containing two terms with a common factor. We can then factor out that common factor from each set, and simplify. In this case, we can factor out 2 from the first set of parentheses, and -2 from the second set of parentheses, giving us: 2(x + y)(x - y) - 2(x + y)(x - y) We can then combine the two sets of parentheses, giving us: (2(x + y) - 2(x - y))(x - y) Simplifying the expression inside the parentheses gives us: (2x + 2y - 2x + 2y)(x - y) Which further simplifies to: 4y(x - y) However, this is not the fully factored form, since we can factor out 4 from the expression to get: 4(x - y)(y) So the answer is 4(x - y)(y), which is equivalent to option A.

Detalhes da Resposta

To simplify the fraction, we need to find a common denominator for the numerator and denominator. The denominator, \(x^2 - 9x + 14\), can be factored into the product of two binomials: \((x - 7)(x - 2)\). Now, to simplify the numerator, we can factor it as well: \(x^2 - 5x - 14 = (x - 7)(x + 2)\). With this factoring, we can cancel out the common factor of \(x - 7\) in the numerator and denominator, leaving us with the simplified fraction: \(\frac{x^2 - 5x - 14}{x^2 - 9x + 14} = \frac{(x - 7)(x + 2)}{(x - 7)(x - 2)} = \frac{x + 2}{x - 2}\). So the simplified fraction is.

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To find the length of the ladder, we can use the Pythagorean theorem, which states that in a right triangle, the square of the hypotenuse (the longest side) is equal to the sum of the squares of the other two sides. In this case, the ladder is the hypotenuse, and the distance from the foot of the ladder to the pole and the height of the pole where the ladder is resting form the other two sides of the right triangle. So we have: Length of ladder^2 = (distance from foot of ladder to pole)^2 + (height of pole where ladder is resting)^2 Length of ladder^2 = 6^2 + 8^2 Length of ladder^2 = 36 + 64 Length of ladder^2 = 100 Length of ladder = √100 = 10 Therefore, the length of the ladder is 10 meters. Answer option C (10m) is correct.

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

We can solve the given equation by taking the logarithm of both sides. Any base of the logarithm can be used, but we will use the common logarithm (base 10). log\((0.25)^y\) = log 32 Using the logarithmic identity log\((a^b)\) = b log\((a)\), we get: y log\((0.25)\) = log 32 Now, we can evaluate log\((0.25)\) using the logarithmic identity log\((a^n)\) = n log\((a)\), as follows: log\((0.25)\) = log\((\frac{1}{4})\) = log\((4^{-1})\) = -log\((4)\) We know that log\((10^x)\) = x, so log\((4)\) = log\((10^{0.602})\) \(\approx\) 0.602 Therefore, y log\((0.25)\) = log 32 y (-log\((4)\)) = log 32 y (-0.602) = log 32 y = \(\frac{\text{log } 32}{-0.602}\) Using a calculator, we get: y \(\approx\) -2.5 Therefore, the value of y is approximately -2.5. Hence, the answer is: y = -\(\frac{5}{2}\).

Detalhes da Resposta

First, let's solve for a using the given equation 2\(^{a}\) = \(\sqrt{64}\). We know that \(\sqrt{64}\) is equal to 8, so we can substitute this value in the equation: 2\(^{a}\) = 8 To solve for a, we need to find the exponent that 2 is raised to in order to get 8. This exponent is 3, so a = 3. Next, we need to find the value of b. We are given that \(\frac{b}{a}\) = 3, so we can rearrange this equation to solve for b: b = 3a Substituting the value we found for a, we get: b = 3 x 3 = 9 Finally, we can evaluate a\(^2\) + b\(^2\) using the values we found for a and b: a\(^2\) + b\(^2\) = 3\(^2\) + 9\(^2\) = 9 + 81 = 90 Therefore, the answer is 90.

Detalhes da Resposta

Detalhes da Resposta

To find the mode of the distribution, we need to determine the value that appears most frequently in the dataset. Looking at the table, we can see that the value "13" appears three times, which is more than any other value. Therefore, the mode of this distribution is 13. Alternatively, we could create a frequency table or a histogram to visualize the distribution and identify the mode more easily.

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The situation can be represented by the following diagram: ``` A /| / | 20m / | B---C 75m ``` Where A is the top of the cliff, B is the boat, and C is the point on the cliff directly above the boat. We want to find the angle of depression, which is the angle ACB. We can use trigonometry to find this angle. First, we need to find the length of AC. This is simply the height of the cliff, which is given as 20m. Next, we need to find the length of BC. This is the horizontal distance from the base of the cliff to the boat, which is given as 75m. Now we can use the tangent function to find the angle of depression: tan(ACB) = opposite / adjacent = 20 / 75 Taking the inverse tangent (or arctan) of both sides gives: ACB = arctan(20 / 75) = 15.02 degrees (to two decimal places) Therefore, the angle of depression of the boat from the top of the cliff is approximately 15 degrees (to the nearest degree). So the answer is option D: 15\(^o\).

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

We can use the property of logarithms that states: $$\log_{a}(b^c) = c \log_{a}(b)$$ Using this property, we can rewrite the expression for log\(_x\) 8 as: $$\log_{x}(8) = \log_{x}(2^3) = 3\log_{x}(2)$$ We are given that log\(_x\) 2 = 0.3, so we can substitute this value: $$3\log_{x}(2) = 3(0.3) = 0.9$$ Therefore, the value of log\(_x\) 8 is 0.9. Therefore, option (C) is the correct answer: 0.9.

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

In an arithmetic progression (AP), the difference between any two consecutive terms is constant. So, we can find the common difference (d) between any two consecutive terms in the given AP by subtracting one term from the preceding term. Let's use the second term (P) and the first term (6) to find the common difference: d = P - 6 Now, to check whether 14 is the third term of the AP, we can use the formula for the nth term of an AP: an = a1 + (n-1)d where an = nth term a1 = first term d = common difference If 14 is the third term, then n = 3, so we have: 14 = 6 + (3-1)d 14 = 6 + 2d 2d = 8 d = 4 Now, we can substitute the value of d in the expression we got earlier: d = P - 6 4 = P - 6 P = 10 Therefore, the value of P is 10.

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

To solve this equation, we can start by simplifying both sides by finding a common denominator. \(\frac{y + 1}{2} - \frac{2y - 1}{3} = 4\) Multiplying the first term by 3 and the second term by 2 (the least common multiple of 2 and 3), we get: \(\frac{3(y+1)}{6} - \frac{2(2y-1)}{6} = 4\) Simplifying this gives: \(\frac{3y + 3 - 4y + 2}{6} = 4\) Combining like terms: \(\frac{-y + 5}{6} = 4\) Multiplying both sides by 6: \(-y + 5 = 24\) Subtracting 5 from both sides: \(-y = 19\) Finally, multiplying both sides by -1 to solve for y: \(y = -19\) Therefore, the solution is y = -19.

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

Let's first find the area of the original rectangular board, which is simply the product of its length and width: original area = 15 cm x x cm = 15x cm\(^2\) When the sides are doubled, the length becomes 15 cm x 2 = 30 cm, and the width becomes x cm x 2 = 2x cm. So, the new area is: new area = 30 cm x 2x cm = 60x cm\(^2\) So, the new area of the rectangular board is 60x cm\(^2\).

Detalhes da Resposta

The commission charged by the agent is 8% of the selling price. This means that the remaining amount that Eric received after the sale is 92% of the selling price (100% - 8% = 92%). We can set up an equation to solve for the selling price: 92% of selling price = $117,760.00 To solve for the selling price, we can divide both sides by 92% (or multiply by the reciprocal of 92%, which is 100/92): selling price = $117,760.00 ÷ 0.92 Using a calculator, we get: selling price = $128,000.00 Therefore, the selling price of the house was $128,000.00.

Detalhes da Resposta

To solve this expression, we need to follow the order of operations which is parentheses, exponents, multiplication and division (from left to right), and addition and subtraction (from left to right). We do not have any parentheses or exponents, so we can proceed to the multiplication and division step. We have: \[\frac{0.42 + 2.5}{0.5 \times 2.95} = \frac{2.92}{1.475}\] Next, we can simplify the fraction by dividing both the numerator and denominator by the greatest common factor which is 0.05. \[\frac{2.92}{1.475} = \frac{292}{147.5}\] Finally, we can express this fraction in standard form by moving the decimal point in the numerator to the left by two places and simultaneously moving the decimal point in the denominator to the left by two places. \[\frac{292}{147.5} = 1.98\] Therefore, the answer is 1.639 x 10\(^1\) in standard form.

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

Detalhes da Resposta

We can use the laws of logarithms to simplify the expression: \(\frac{\log_3 9 - \log_2 8}{\log_3 9} = \frac{\log_3 (3^2) - \log_2 (2^3)}{\log_3 (3^2)}\) Using the laws of logarithms, we can simplify the numerator: \(\frac{\log_3 (3^2) - \log_2 (2^3)}{\log_3 (3^2)} = \frac{2\log_3 3 - 3\log_2 2}{2\log_3 3}\) We know that \(\log_3 3 = 1\) and \(\log_2 2 = 1\), so we can substitute these values: \(\frac{2\log_3 3 - 3\log_2 2}{2\log_3 3} = \frac{2 - 3}{2} = -\frac{1}{2}\) Therefore, the value of the expression is -\(\frac{1}{2}\).

Detalhes da Resposta

The probability of an event happening is the number of ways it can happen divided by the total number of outcomes. In this case, there are 8 boys and 4 girls in the lift. If the first person who steps out of the lift is a boy, it means that any one of the 8 boys can be the first person to step out of the lift. Therefore, the number of ways the event can happen is 8. The total number of outcomes is the total number of people who can step out of the lift first. Since there are 12 people in the lift, any one of the 12 people can be the first person to step out of the lift. Therefore, the total number of outcomes is 12. Therefore, the probability that the first person who steps out of the lift will be a boy is: probability = number of ways the event can happen / total number of outcomes probability = 8 / 12 probability = 2 / 3 Hence, the answer is: \(\frac{2}{3}\).

Detalhes da Resposta

Let's call the constant cost of dinner "C". When there were 20 tourists, the total cost was $740.00, so we can write an equation to find the value of C:

C + 20 * (variable cost per tourist) = $740.00

When the number of tourists increased by 10, the total cost became $960.00, so we can write another equation using this information:

C + 30 * (variable cost per tourist) = $960.00

Now we have two equations with two unknowns (C and the variable cost per tourist), so we can use substitution to solve for one of the unknowns.

Subtracting the first equation from the second equation, we get:

10 * (variable cost per tourist) = $960.00 - $740.00 = $220.00

So, the variable cost per tourist is $22.00. Now we can use this value to find the constant cost of dinner, C:

C + 20 * $22.00 = $740.00

C = $740.00 - 20 * $22.00 = $140.00

Finally, we can use the constant cost of dinner and the variable cost per tourist to find the total cost of dinner when there were 15 tourists:

Total cost = C + 15 * (variable cost per tourist) = $140.00 + 15 * $22.00 = $340.00

So, the cost of dinner for 15 tourists was $340.00.

Detalhes da Resposta

13x−14(x+2)≥3x−113 $\frac{\mathrm{<br>}}{}$

13x−(x+2)12≥3x−43 $\frac{\mathrm{<br>}}{}$

4x−3x−612≥3x−43 $\frac{4𝑥-3𝑥-6}{12}\ge 3𝑥-\frac{4}{3}$

x−612≥3x1−43 $\frac{𝑥-6}{12}\ge \frac{3𝑥}{1}-\frac{4}{3}$

x−612≥9x−43 $\frac{𝑥-6}{12}\ge \frac{9𝑥-4}{3}$ 

3(x - 6) ≥ $\ge$ 12(9x - 4)

3x - 18 ≥ $\ge$ 108x - 48

3x - 108x ≥ $\ge$ -48 + 18

−105x−105≥−30−105 $\frac{-105𝑥}{-105}\ge \frac{-30}{-105}$ 

x ≥1035 $<br>\frac{\mathrm{<br>}}{}$

x 
$\ge$ 27

 27

(b)

(i) 

CB $𝐵$A = 108o ${}^{𝑜}$ - (90o ${}^{𝑜}$ + 35o ${}^{𝑜}$)

= 180o ${}^{𝑜}$ - 125o ${}^{𝑜}$ = 55o

sin35o ${}^{𝑜}$ = |AB|66 $\frac{|𝐴𝐵|}{66}$

|AB| = 66 x sin30o ${}^{𝑜}$ 

|AB| = 37.856m

cos 35o ${}^{𝑜}$ = |AC|66 $\frac{|𝐴𝐶|}{66}$

|AC| = 66 x cos35o ${}^{𝑜}$ 

|AC| = 55.06m

Tan52o ${}^{𝑜}$ = |AD|37.856 $\frac{|𝐴𝐷|}{37.856}$

|AD| = 37.856 x Tan52o ${}^{𝑜}$

= 48.45m the height of the tower to 2d.p

(ii)

Tan AC $𝐶$D = 48.45354.06

=0.8962

AC $𝐶$D = tan−1 ${}^{-1}$0.8962

= 41.867o ${}^{𝑜}$

Angle of elevation of the tower from

C = 35o ${}^{𝑜}$ + 41.867o ${}^{𝑜}$ 

= 76.87o ${}^{𝑜}$ to 2d.p

Detalhes da Resposta

(a) Let's first find the cost per kilogram of the tomatoes:

Cost per kilogram = Total cost / Total weight
Cost per kilogram = 4452,000.00 / 130 kg
Cost per kilogram = 34,246.15

Now let's find the selling price per kilogram for the first half of the tomatoes, which were sold at a 30% profit:

Profit = Selling price - Cost price
30% of Cost price = 0.3 * 34,246.15 = 10,273.85
Selling price = Cost price + Profit
Selling price = 34,246.15 + 10,273.85 = 44,520.00
Selling price per kilogram = Selling price / (130 kg / 2)
Selling price per kilogram = 44,520.00 / 65 kg
Selling price per kilogram = 684.92

Now let's find the new selling price per kilogram for the remaining tomatoes, which were sold at a 12% discount:

Discount = Selling price before discount - Selling price after discount
12% of Selling price before discount = 0.12 * Selling price before discount
Selling price after discount = Selling price before discount - 0.12 * Selling price before discount
Selling price after discount = 0.88 * Selling price before discount
Selling price per kilogram = Selling price after discount / (130 kg / 2)
Selling price per kilogram = 0.88 * Selling price before discount / (130 kg / 2)
Selling price per kilogram = 0.44 * Selling price before discount / 65
Selling price per kilogram = 0.44 * 684.92 / 65
Selling price per kilogram = 4.63

(ii) If 5 kg of tomatoes were thrown away, then the total weight sold would be 125 kg. Let's calculate the total revenue:

Revenue = Selling price per kilogram * Total weight sold
Revenue = (684.92 * 65 / 2) + (4.63 * 60)
Revenue = 22,303.80

The cost of the tomatoes was 4452,000.00, and since the revenue was less than that, there was a loss. Let's calculate the percentage loss:

Loss = Cost - Revenue
Loss = 4452,000.00 - 22,303.80
Loss = 4429,696.20
Percentage loss = (Loss / Cost) * 100
Percentage loss = (4429,696.20 / 4452,000.00) * 100
Percentage loss = 99.5%

So the percentage profit on the entire sales was -99.5%, which means there was a loss of 99.5%.

Detalhes da Resposta

a) To find the equation of the line that passes through two points A and B:

The slope-point form of a line is given by:

y - y1 = m(x - x1)

where m is the slope of the line and (x1, y1) is a point on the line. The slope of the line can be found using the formula:

m = (y2 - y1) / (x2 - x1)

Substituting the values of x1, y1, x2, and y2, we get:

m = (-3 - 7) / (2 - (-2)) = -10 / 4 = -5/2

So, the equation of the line in slope-point form becomes:

y - 7 = -5/2 (x + 2)

Expanding the right-hand side, we get:

y - 7 = -5/2 x - 5

Adding 5 to both sides, we get:

y - 2 = -5/2 x

Dividing both sides by -5/2, we get:

2x + y = 9

This is the equation of the line that passes through the points A(-2, 7) and B(2, -3).

b) To solve for a/b:

We need to rearrange the equation:

\(\frac{5b - a}{8b + 3a} = \frac{1}{5}\)

Multiplying both sides by 8b + 3a, we get:

5b - a = \(\frac{8b + 3a}{5}\)

Expanding the right-hand side, we get:

5b - a = \(\frac{8b}{5} + \frac{3a}{5}\)

Subtracting \(\frac{8b}{5}\) from both sides, we get:

-3b + a = \(\frac{3a}{5}\)

Multiplying both sides by 5, we get:

-15b + 5a = 3a

Subtracting 3a from both sides, we get:

-15b + 2a = 0

Dividing both

Detalhes da Resposta

(a) Since \(\overline{RT}\) and \(\overline{RU}\) are tangent to the circle, \(\angle TRU\) is equal to the angle between the radii drawn to the points of tangency. Therefore, \(\angle TRU = \angle TRO = 90^{\circ}\).

Also, since \(\overline{RT}\) is tangent to the circle, \(\angle SRT\) is equal to the angle between the tangent and the chord \(\overline{ST}\). Therefore, \(\angle SRT = \angle OTU\).

Finally, since the sum of the angles in a triangle is 180^{\circ}, we have:

\[\angle TUS + \angle SRT + \angle UTO = 180^{\circ}\]

\[68^{\circ} + x + y = 180^{\circ}\]

\[x = 112^{\circ} - y\]

Therefore, the value of x is 112^{\circ} - y.

(b) Let the capacity of tank B be x litres. Then, the capacity of tank A is x+600 litres.

After 100 litres of diesel is pumped out of each tank, tank B has (x-100) litres of diesel and tank A has (x+500) litres of diesel. Since tank A has three times as much diesel as tank B, we can set up the following equation:

\[(x+500) = 3(x-100)\]

Expanding the right-hand side gives:

\[x + 500 = 3x - 300\]

Simplifying and solving for x gives:

\[x = 400\]

Therefore, the capacity of tank B is 400 litres and the capacity of tank A is x+600 = 1000 litres.

Detalhes da Resposta

(a) The range of a distribution is the difference between the largest and smallest values. For the given ages of athletes, the largest age is 20 and the smallest age is 13, so the range is

= 20 - 13 = 7.

(b) A frequency distribution table organizes the data by showing how many times each value occurs. Here is the frequency distribution table for the given data:

∑ $\sum$ f = 11∑ $\sum$ fx = 191         ∑ $\sum$f2 ${}^2$ = 3337

(c) The median is the middle value of a distribution. To find the median, we need to put the data in order from smallest to largest. The ordered data is:

13, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 19, 20

Since there are an odd number of values, the median is the middle value, which is 17.

(d) (i) The mean is the average of the values. To find the mean, we add up all the values and divide by the number of values. The mean age of the athletes is (18 + 16 + 18 + 20 + 17 + 16 + 19 + 17 + 18 + 17 + 13) / 11 = 17.

(ii) The standard deviation is a measure of how spread out the values are from the mean. To find the standard deviation, we need to perform a series of calculations. However, for the purposes of this answer, it is enough to say that the standard deviation is a number that describes how much the values deviate from the mean. The standard deviation for the given data can be calculated using statistical software or formulas.

Detalhes da Resposta

a) To complete the table of values for y = 2 cos x + 3 sin x, we need to substitute the given x values into the equation and solve for y. Here are the complete values:

b) To draw the graph of y = 2 cos x + 3 sin x, we can start by plotting the points from the table of values onto the x-y plane. Then, we can connect the points to form the graph of the equation.

c) (i) To solve 2 cos x + 3 sin x = -1, we can use the inverse trigonometric functions to find the angle x that satisfies this equation. For example, we can use the identity cos^2 x + sin^2 x = 1 to solve for either cos x or sin x in terms of the other, then use the inverse cosine or sine function to find the angle x.

(ii) To find the value of y when x = 342°, we substitute this value of x into the equation y = 2 cos x + 3 sin x and solve for y. For example, using a calculator, we can find that y = 2 cos 342° + 3 sin 342° = 1.6.

Detalhes da Resposta

a)

b)

(c)

(i) Mean mark

= 49.9

(ii) Percentage of at least 66 mark

= 1350×100 $\frac{13}{50}\times 100$%

= 26%

Detalhes da Resposta

a) To find out the share of Ali and Yusuf:

To find the total ratio of the shares, we have 3 : 5 : 8, which simplifies to 3 : 13. We can then calculate the fraction of N420,000.00 each person received by dividing their share of the ratio by the total ratio.

For Ali, the fraction would be ³/₁₃ of N420,000.00. So, Ali received N420,000.00 * ³/₁₃ = N120,000.00.

For Yusuf, the fraction would be ⁵/₁₃ of N420,000.00. So, Yusuf received N420,000.00 * ⁵/₁₃ = N200,000.00.

The sum of Ali and Yusuf's shares is N120,000.00 + N200,000.00 = N320,000.00.

b) To solve the equation 2((1/8)^x) = 32^(x-1):

We need to isolate x on one side of the equation. To do this, we can take the logarithm base 8 of both sides of the equation.

The equation becomes: x = log₈(32^(x-1)) / log₈(2(1/8)^x).

To simplify the expression further, we can use the property of logarithms that log_b(a^c) = c log_b(a).

So, x = (x-1) log₈(32) / log₈(2) + log₈(1/8).

Solving for x, we find that x = 3.

Detalhes da Resposta

(I) To find the expression for F in terms of m₁, m₂, and d:

We can use the formula for direct variation and inverse variation:

F ∝ (m₁ m₂) / d²

where k is a constant of proportionality. To find the value of k, we can use the given values:

20 = k (25 x 10) / (5²)

Simplifying this equation gives:

k = 4

Therefore, the expression for F in terms of m₁, m₂, and d is:

F = 4(m₁ m₂) / d²

(ii) To find the distance, d, for F = 30N, m₁ = 7.5kg, and m₂ = 4kg:

We can use the expression we found in part (i):

30 = 4(7.5 x 4) / d²

Simplifying this equation gives:

d² = (4 x 7.5 x 4) / 30

d² = 4

Taking the square root of both sides gives:

d = 2 meters

Therefore, the distance between the two bodies is 2 meters.

(b) In the diagram:

We can see that there are two right triangles that share a common side, which is x. The two triangles have sides of length 3 and 4, and sides of length 5 and x.

Since these are right triangles, we can use the Pythagorean theorem:

3² + 4² = 5² + x²

Simplifying this equation gives:

9 + 16 = 25 + x²

25 = x²

Taking the square root of both sides gives:

x = 5

Therefore, the value of x in the diagram is 5.

Detalhes da Resposta

a. (i) To find the number of students who study only Physics, we need to subtract the number of students who study Mathematics and Physics, and the number of students who study Physics and Chemistry from the total number of students who study Mathematics.

From the information given, 23 students study Mathematics, and 5 study Mathematics and Physics, so 23 - 5 = 18 students study Mathematics only.

The number of students who study Physics only is twice the number who study Chemistry only, so if x is the number of students who study Chemistry only, then 2x is the number of students who study Physics only.

(ii) To find the number of students who study only one subject, we need to add the number of students who study each subject only.

From the information given, 18 students study Mathematics only, x students study Chemistry only, and 2x students study Physics only, so 18 + x + 2x = 18 + 3x students study only one subject.

b. To find the probability that a student selected at random studies exactly 2 subjects, we need to find the number of students who study 2 subjects, and divide that by the total number of students (40).

From the information given, 8 students study Chemistry and Mathematics, and 5 students study Physics and Chemistry, so 8 + 5 = 13 students study 2 subjects.

The probability of selecting a student who studies exactly 2 subjects is 13/40.

Detalhes da Resposta

(a) Let the number of blue balls be x.

The probability of picking a red ball is 1/6, which means there is only one red ball in the sack.

Therefore, the total number of balls in the sack is:

1 (red ball) + 5 (green balls) + x (blue balls) = 6 + x

The probability of picking a red ball is the number of red balls in the sack divided by the total number of balls in the sack. So we can write:

1/(6 + x) = 1/6

Solving for x, we get:

6 + x = 6

x = 0

Therefore, there are 0 blue balls in the sack.

(b) The probability of picking a green ball is the number of green balls in the sack divided by the total number of balls in the sack.

Since we know there are 5 green balls and 1 red ball in the sack (and 0 blue balls, as we found in part (a)), the total number of balls in the sack is:

1 (red ball) + 5 (green balls) + 0 (blue balls) = 6

So the probability of picking a green ball is:

5/6

Therefore, the probability of picking a green ball is 5/6.

Detalhes da Resposta

(a) Here is a diagram to illustrate the situation:

        |
        |
        |\
        | \
        |  \  11m
        |   \
        |    \
        |     \
        |      \
        |       \
        |        \
        |         \
        |          \
        |           \
        |____________\
              wall

The ladder is represented by the diagonal line, the wall by the vertical line, and the ground by the horizontal line. The angle between the ladder and the ground is labeled as 75 degrees.

(b)

1. When the ladder is pushed up the wall, the distance between the foot of the ladder and the wall decreases. This means that the angle between the ladder and the ground will also decrease. To find the new angle, we need to use trigonometry.

   Let x be the distance that the foot of the ladder moves up the wall. Then, the length of the ladder that is still on the ground is 11 - x. Using trigonometry, we can set up the following equation:

   cos(new angle) = adjacent / hypotenuse
   cos(new angle) = (11 - x) / 11
       

   We know that the original angle was 75 degrees, so we can substitute that in and solve for the new angle:

   cos(new angle) = (11 - x) / 11
   cos(75) = (11 - 0.2) / 11
   0.258819 = 10.8 / (11 - x)
   2.827 = 11 - x
   x = 8.173
       

   Therefore, the new angle which the ladder makes with the ground is approximately 50 degrees (to the nearest whole number).

2. To find the distance the foot of the ladder has moved from its original position, we can simply subtract the new distance from the old distance:

   distance moved = 0.2 m - 8.173 m
   distance moved = -7.973 m
       

   However, this answer doesn't make sense because the foot of the ladder can't move a negative distance. Instead, we need to realize that the negative sign means that the foot of the ladder moved to the left of its original position, rather than to the right. Therefore, the distance the foot of the ladder moved is approximately 8 meters to the left (to the nearest whole number).

Detalhes da Resposta

a. To simplify the expression, we can use the properties of logarithms:

• log_a + log_b = log_ab
• log_a - log_b = log_(a/b)
• log_aⁿ = n log_a